An Ag-infiltrated nanocomposite LSCF (La0.6Sr0.4C0.2Fe0.8O3-delta)-YSZ (yttria stabilized zirconia) oxygen electrode is prepared for co-electrolysis of steam and CO2. Scanning electron microscopy (SEM) associated with energy dispersive X-ray spectroscopy (EDS) is employed to verify that nano-Ag particles are formed into the porous LSCF-YSZ electrode. Polarization curves and electrochemical impedance spectra (EIS) of the cell as well as long-term durability are investigated. In comparison with the Ag-free cell, the Ag-loaded cell exhibited improved performance and long-term stability when 45% H2O, 45% CO2, and 10% H-2 is introduced as inlet gas. With infiltration of metal Ag, the ohmic resistance of the cell decreases from 0.14 Omega cm(2) to 0.11 Omega cm(2), and the polarization resistance from 0.30 Omega cm(2) to 0.17 Omega cm(2) at 800 degrees C. No significant deterioration of the Ag-infiltrated cell is observed when operating for 200 h at 1.3 V and 750 degrees C. With respect to varied H2O/CO2 ratio (1:2, 1:1, and 2:1) in feed gas, higher H2O percent content is resulted into higher cell performance, despite the fact that varied inlet gas composition did not dramatically influence the cell performance. (C) 2016 Published by Elsevier B.V.